So OP, you used to have a full mast while urinating, and you wish this was still the case? I'm so confused...
Funny side note: I actually popped 50mg of V before meeting a girl for drinks at midnight on a Saturday recently (we were basically just meeting to hook up). Well, every time I get up to go to the bathroom, I get a hard on from hell. This made peeing in the only damn toilet the bar had really difficult, and I was getting more on the wall than in the toilet. After excusing myself several times to try and essentially fail to empty my bladder, I ended up whipping it out and peeing in the sink, using my left hand to block the stream and channel it into the sink. It was absurd but felt sooo good
Moral of the story: trying to pee with a boner sucks. I don't know why you would want this.